Half-blood Hogwarts
by Shadowhunter of Alicante
Summary: The giant war is over, the demigod think that all the danger is gone. How wrong they are. Percy is sent to England to protect Harry Potter, the chosen one, but what happens when a new prophesy is issued, and old enemies become new friends. Please read, i promise it's not your normal Harry Potter, Percy Jackson crossover.
1. Half blood hogwarts

Changes from the original series  
>Okay this is basically all the changes i have made from the original series. One day i might re write the series to fit in with this story but at the moment i am not, so here it goes.<p>

1. Annabeth and Thalia have changed places. Annie is now the Lieutenant of the hunt, and Thalia is with /2. The first great prophesy was completed when Percy was 14, so Percy is now 16. This just means that i can have Percy in Harry's year and include the 7 from the prophesy ( which by the way included Thalia instead of Annabeth. )

3. Percy got a second curse of Achilles during the giant war, along with Nico and Jason

4. The next part is an established couples list.

-Percy and Thalia (THE FEEELS!)

-Jason and Piper

-Frank and Hazel

-Leo and Calypso

-Travis and Katie

-Connor and Miranda

-Will and Nico

-Chris and Clarisse

5. The Romans and Greeks get along. Especially considering their Praetors are both going out with greeks.

Finally i am only going to disclaim once as i can't be bothered to do it every chapter.

Percy: so do it

Me: i'm getting

Percy: just do

Me: why don't

Percy: because i do own

Me: no you don't you are a fictional character, to be honest i'm not sure how this conversation is happening.

Percy: *silence*

Me: thought so. Anyway i own neither Percy Jackson, Heroes of Olympus or Harry Potter. They all belong to Rick Riordan and JK Rowling.


	2. Prologue

Dumbledore paced his office with a stern grimace distorting his features. His biggest enemy, Lord Voldemort, had allied himself with the newly reformed titans, led by Lord Kronos and the giants, lead by Lady Gaea. The only reason Dumbledore knew of this was because he was a demi-god himself, a son of Hecate. He knew that the wizards stood no chance if the greek monsters attaked. Magic was, of corse, directly ineffective against monsters. Oh well, time to call an old friend.

Dumbledore walked over to the small fountain he kept in the corner of his room. He cast a quick enchantment causing the water to jump up and make a thin veil of mist. Rummaging around in his cloak pocket he pulled out a single golden drachma, and tossed it into the mist.

"Iris, goddess of the rainbow, show me Chiron, Camp half-blood."

The mist shimmered for a minute, and Dumbledore was afraid it hadn't worked. All of a sudden the mist developed colour and stood there, in centaur form was Chiron, immortal trainer of heroes.

"Chiron!" The centaur turned away from his archery class. A big smile crossed his face when he saw his old student.

"Ah Albus, how lovely to see you. 65 years i believe it's been. As glad as i am to see you, i sense this is not good news." Dumbledore nodded grudingly.

"Yes, you see, the wizarding worlds greatest enemy, Lord Voldemort, has allied himself with the titan Lord Kronos and Primordial Lady Gaea." At both names Chiron's smile slowly slid off of his face.

"B-but Percy has defeated both of them." Dumbledore had no clue who Percy was, but he assumed he was the greek's Harry.

"Well, i did some research some years ago and learnt that magic is directly ineffective against greek monsters, so i am going to have to ask you for a favour. Can you send a team of demi-gods to help defend this school?" Dumbledore was slightly anxious as to Chiron's answer. If the look of pure terror on Chiron's face was anything to go by, Dumbledore might end up being disapointed. After a few moments Chiron clicked his fingers.

"I shall send Perseus himself." Immediately Dumbledore was curious.

"One demigod? Will he be enough?" Chiron looked about ready to burst with pride.

"Percy Jackson may well be the greatest demigod ever to live. When he was 10 he defeated the Minotar and one of the furies before he even knew he was a demigod. Then he defeat Ares and retrieved the master bolt after only months of training. When he was 11 he went to the sea of monsters and recovered the golden fleece. Then, the year after that, he rescued Artemis, battled Atlas and held the sky. At 13 he led a group of demigods into the labrinth, he helped find Pan and also destroyed a large part if Kronos' army. At 14 he completed the first great prophesy by leading the demigods and huntress' to battle in New York. He battled Kronos and managed to convince his host, a son of hermes, to help kill himself. After that war, Percy's memory was removed and he was sent to camp Jupiter. He then freed Thanatos and recovered the fifth legions eagle. He then went to the old Rome and fell into Tartarus. After escaping and helping close the doors of death he battled Gaea one on one...and WON. As much as it pains me to send him into another war, he is the only one who is strong enough alone." To say Dumbledore was surprised would be an understatement.

Dumbledore had had a difficult life. To begin with he was a demigod, and that was bad enough, but with Grindlewald and now Voldemort, Dumbledore was sure no-one could beat him in the who-has-had-the-weirdest-life game. Yet here was a 16 year old who had been faced with challenges even Dumbledore would want to run from. This Percy was truly beginning to intrigue Dumbledore.

"Hmm, he would be most helpful. Thank you for this Chiron i do owe you one...oh and before you go can you tell me Percy's main traits." Chiron looked oddly at the old headmaster.

"If i may ask, why do you want to know them?"

"You see to gain a wand, the wand must choose the wizard. As Percy's arrival here may cause much curiosity, i can just tell his traits to our best wand maker Olivander. I shan't burden him with creating it, i am hoping that my mother will, if she is still on good terms with the demigods." Chiron's face took on a wistful look.

"Yes she is...as for Percy...what can i say. He is the loyalist idiot i know. He would, as Athena would say, destroy the world to save a friend. He is also the humblest of all heroes. He is so humble in fact that he still trains vigorously to try and improve futher. As a son of Poseidon he is very good in or around water, in fact it rejuvenates him. As much as he has done, the deaths of his friends weigh heavily on his shoulders. He hasn't and i don't think will ever forgive himself for their deaths." After all that, Dumbledores curiosity turned to respect. He was truly eager to meet Percy.

"Okay. Thank you Chiron, i shall tell Olivander and send my informant, to deliver the wand and bring Percy in one weeks time." Chiron nodded. Behind Chiron, Dumbledore could hear a camper calling.

"Well thats Thalia, i had better be going. I shall expect your informant in a week, Goodbye Albus."

""Goodbye Chiron." The centaur swiped though the mist and the image faded. Well time to go tell the order.

**12 GRIMAULD PLACE**

"Sirius sat in his usual seat, at the head of the table surveying the members of the order. Lupin, Tonks, Molly, Arthur, Bill and Fleur were all talking, trying to figure out why Dumbledore called this meeting. All of a sudden the fireplace was filled with green flames. The order sat up straighter, hoping for Dumbledore. Instead Moody and Shacklebolt stepped out into the room.

"Sorry we are late. Got a bit caught up in the department of mysteries." Moody said, his accent slurring his words. Everyone sunk back into their chairs and the quiet chatter began again. Around 5 minutes later the fireplace ignited again.

"Hello everyone, i am so sorry for calling this meeting on such short notice, but i have some most pleasant news." Dumbledore looked practically giddy. It was a strange thing to see on a man who was nearly 115.

"Well then, go on." Moody, always the patient, spoke up. Everyone looked towards Dumbledore. Apparently Moody's attitude hadn't put a dampener on his happiness.

"It seems as though, we have some new allies." For the next half an hour, Dumbledore went on to explain the whole world of Gods, Demigods and Titans. To say the order was surprised would be an undersatetment. After much argument, and a little cursing on Moody's account, they eventually believed him.

"So you're saying dat we will have some 'elp in dis war?" Fleur spoke up. Dumbledore looked at her, an unidentifiable expression crossed his face.

"Well yes and no. You see, my old friend Chiron is sending just one demigod, a child named Percy." Everyone looked at the headmaster shocked. Just one child?

"Surely your not serious Dumbledore." Lupin said, still gaping at the old man. Dumbledore looked a little sceptical too, but managed to hide it well.

"Well, from Chiron's explanation this Percy is very powerful, maybe more than me." All the orders jaws dropped futher. A child more powerful than Dumbledore?

"Dumbledore, when will the boy arrive." Sirius asked, earning a small mischievous glance from the headmaster.

"Well Sirius, you are the one i really had to speak to about this. You see, the demigods are located in America and young Percy has never been introduced to the magical world, so i was hoping to send you, along with a custom made wand, to him." Sirius looked both happy and apprehensive. What if the kid was another Draco, power hungry and egotistical? Sirius pushed the thoughts aside and smiled warmly at Dumbledore.

"Sure, when am i to fetch him?"

"In one weeks time."


	3. Chapter 1

PERCY POV

Before anything, i think I should explain that Chiron has explained his plan to me, and i'm not happy one little bit. I mean, i just helped win two wars, and now they throw me into another one. Plus i have to leave my spark plug behind. Yep, Thalia's going to be pissed.

Anyway, todays the day. The rest of camp have been taken on a little outing, courtesy of Artmeis, to improve on their tracking skills. Needless to say, i'm so happy i'm not Nico right now.

"Percy, i do hope you have packed. Dumbledores informant will be here in a few minutes." Chiron shouted through my door. Rolling out of bed, i managed to find my bag, Riptide and t-shirt, before answering the door to Chiron. He just shook his head wistfully at me.

"Perseus Jackson, you are going to be the death of me." I laughed a little at that as i closed the door to my cabin. Walking through an empty camp was really eerie. No clang, as Clarisse killed some poor Hermes kid. No screaming as Leo flirted with yet more nymphs, despite his girlfriend Calypso (who he saved thank Zeus). No shouting as Connor and Travis are shunned for yet another prank.

"Wait right here Percy." Chiron said as he galloped away. A few seconds later he returned with a small bag. He handed it over to me.

"That bag is enchanted so that you can pull any weapon you like out of it. It also has an endless supply of Drachma and Galleons. If you get in any real danger blow the whistle in their and blackjack will be teleported straight to you. You can also contact Mrs O'Leary if you wish." I was stunned. Still a little bewildered by the bag, i stuck my hand in. When i pulled it back out there was a silver trident which stood 6'4 and had an excellent balance on it.

"Dad." I whisped. Obviously Chiron heard because he nodded smiling a little.

"Yes a gift from you father, use it wisly." I put the trident back in the bad and waited. True to Chiron's word, a few seconds later there was a pop, and a disheveled ( thank Annabeth for my amazing vocab. ) man stood there, staring at us in ore. Specifically Chiron.

"Well, i never though i'd see the day when i'd be meeting a Centaur as a friend. Nice to meet you Chiron, and Perseus. I have heard a great many things about you." He said, his british accent thick, yet not posh. The only way i can describe him would be to say that he is an older Nico. He wore a long black coat which covered his entire top half, and most of his legs. On his feet was a pair of dull looking boots, which looked as if they had seen better days. He had curly black hair and dark brown eyes, yet unlike Nico, looking cold and dark, this man seemed to radiate hospitality.

"You too. I take it your Dumbledore's informant." The man nodded.

"Sirius Black, at your servise." And the surname Black, seriously. Nico would love this guy. Sirius directed his warm gaze back to me.

"So this is the great Perseus Jackson, wow. Its a great honour to meet you." Sirius said, extending his hand for me to shake. I took it tentatively (ooh look another big word)

"Err you too?" I didn't mean for it to come out as a question yet it did. Sirius laughed a little, them removed a small rectangular box from an inside coat pocket.

"I suppose you'd like your wand now?" The way in which Sirius said it made me giddy. I couldn't help but nod franticly, causing both the adults to laugh. Sirius placed the box in my hand, and when i opened it, my breath hitched.

"12 inches, Kaya, Rigid and the core is a chimera scale fragment. A very beautiful, and very powerful wand. In fact this may just be the second most powerful wand right next to the elder wand. However, unlike the elder wand, this wand has a clear affinity for water and defensive spells and charms. Not so good with divination it seems." Wow, second most powerful. To be honest, that wasn't what made me love the wand. It was the affinity to water that did.

"Umm, Chiron? How am i supposed to do magic if i don't have magical blood?" Chiron looked down at me and smiled.

"Lady Hecate has blessed that wand so that you can say what you want to do in ancient greek, flick the wand, and it will happen. This is a permanent gift from lady Hecate, i trust you not to abuse it." Wow, who knew Hecate was so nice. I must remember to sacrafice to her next time i eat.

"I won't don't worry." Their was a brief awkward silence, before Sirius broke it with a small cough.

"If thats all, we had better be going Perseus." I flinched at the use of my full name.

"Please, call me Percy. Just Percy." Sirius laughed and rested a hand on my shoulder, despite the fact that i was taller than him.

"Okay, Just Percy." And with that we popped away.

**HARRY POV**

"What a boring end to a boring day. Don't get me wrong, i loved the people at Grimauld place, i just wish something would happen. It was still two weeks until school, and one week until out yearly visit to Diagon ally.

"Harry dear, can you and the other children come down here?" Molly Weasley called up from the kitchen.

"Okay." I quickly ran into the living room and rounded the guys up. Ron walked quicker so he came in line with me.

"Did my mum say why she wanted us?" He asked. I just shook my head no.

When we got to the kitchen the whole order was there. And when i say whole, i mean all of them. Tonks, Lupin, Shacklebolt, Moody, Bill, Fleur, Molly, Arthur and Dumbledore. Actually, now come to think of it, where is Sirius.

"Umm, Mrs Wealey, were is Sirius." Molly turned to face me and the others.

"He should be here. Oh and Harry, please call me Molly. Mrs Weasley makes me feel old." We all laughed at that, and took our places at the enormous table. After five minutes of waiting, mad-eye hit the table with his hand.

"Will he just bloody-." He was cut of by the familiar pop of apperation. Stood at the head of the table was Sirius and...someone i didn't know. The new boy looked to be around 6"5, tan and ripped. Despite his body, he looked to be our age. Let me put this lightly, this guy was hot. Anybody could see that. He had a very soft face with two large sea-green eyes that drew you in. His hair was a deep ebony and was very messy, but it suited him. He had a surfers look about him, with a beaded necklace on and a pair of shorts. His top read camp half-blood. Hmm, strange name.

"Ahh, here he is. Everyone, i would like to introduce you to our new *cough* transfer student, Perseus Achilles Jackson." By the way the adults looked at Perseus, i knew they knew something we didn't about him.

"Please, just call me Percy." I heard a sigh and turned to see Ginny and Hermione staring at Percy gooey eyed, well looks like someone has a crush.

"Yes, well, Percy here is from America and has trained using magic in Ancient Greek. His headmaster, professor Brunner, though that his transfer may help him expand his knowledge." Wow, this guy must be good for them to send him half way across the world. Percy looked around at each of our faces, studying us subtly.

"Umm, i don't want to be rude, but i don't know anyone apart from Dumbledore and Sirius so..." He scratched the back of his head nervosly, suddenly becoming very interested in the floor. At least he's modest, not another Draco.

"Oh of corse. I'm Molly Weasly, and this is my husband Athur." Molly got up and stood next to Percy. She pointed a finger at the twins.

""Thats Fred and George." Percy waved a them a little.

"Nice to-

"Meet you-

"Mate!" Ugh they are doing that twin thing again. Percy smiled widely at them. Nice to know he likes a joke. Molly pointed towards the rest of the order, all of which said their hello's to Percy.

"Those are Ronald and Ginevra. Just call them Ron and Ginny though." They both said their hellos, Ron whilst stuffing his face, earning a scowl from Molly, and a laugh from Percy. Finally, Molly pointed towards me and Hermione.

"And last but not least, Harry and Hermionie. They don't normally stay here, but they are staying so we can all go to diagon ally together." Percy just nodded along, despite the fact that he obviously had no clue what diagon ally was. Molly pointed to the seat between me and Hermione, were Percy soon sat. Hermione's face was going redder by the second.

"So Percy, what kind of magic are you good at?" George asked. Molly looked at him like he'd drowned a rat, but Percy still answered.

"Well, i'm best at water magic, which ultimately earned me the name seaweed brain. But anything to do with animals or the sea and i'm there." We all smiled a little.

"Seaweed brain?" Fred asked.

"Yeah, according to my best friend, my brain is full of kelp because i swim too much. Who says you cant spend 7 hours swimming? Pft."

"7 hours!?" Ginny exclaimed. By now the chatter between the adults had halted. Percy just grinned at us all.

"Yeah, i just love the water. Some people find it wierd, but it's where i'm at my best." Everyone stared at Percy in shock.

"So, you do you magic in ancient greek. How does that work?" Hermione asked. Always inquisitive that one.

"Well, i just say what i want done, with specific wand movements of corse, and hey presto." Wow, Percy certainly was going to make this year interesting.


	4. Chapter 2

1 week later - RON POV

It is official. Percy is the coolest guy to have ever walked this earth. When I first saw him, I though he'd be snobby and pompous because of his looks, but if anything he's the opposite. He is always chilling, yet still manages to go out of his way to help people. He's funny, honest, loyal. The list goes on. Plus he is a amazing athlete. We have already roped him into Quidich trials, if he is in Griffindoor. Heck, I can see why Hermione and Ginny drool after him.

"Come on kids, don't want to be late." Mum shooed us towards the fire place. Percy had a look of confusion all over his face. I nudged him a little.

"Hey mate, you never flooed before?" He shook his head no.

"Just copy what the others do." Harry went first, followed by dad, Ginny, Fred, George and mom. Next it was Percy.

"Okay, so i just say Diagon ally?" He asked sheepishly.

"Yup. Just say that, nothing else." He nodded, then threw the power down whilst saying.

"Diagon ally." I breathed a sigh of relief when he left. At least we didn't have another Harry incident. I grabbed a handful of floo powder, stepped into the fireplace, and tossed it at my feet.

"Diagon ally." With in seconds I was in Diagon ally, surrounded by the Weasley crew and friends.

"Okay we will split up so this is done quicker. Fred, George, and Harry, you can go together. Hermione and ginny, you can too. Ron, you go with Percy. Happy shopping." My mum said as she and dad walked of to Merlin knows where.

"Your moms really nice." Percy said as we made our way towards madam Malkins. I nodded. I may give her alot of greif, but I do love my mom. We arrived at the store front within seconds.

"Ahh hello. New student I see. Hogwarts is it? Lets get you fitted." Madam Malkins rushed Percy into the back room, a look of terror on his face. I couldn't help but laugh to myself. Around five minutes later Percy emerged, with Malkins hot on his heels.

"Come back in twenty minutes, they should be ready by then." With that we exited the store.

"Where do you want to go now?" I asked. Percy tilled his head to the side in though, then snapped his finger suddenly.

"How about a pet?" He said. I stared at him questioningly.

"Don't you already have an owl." He shook his head.  
>"At my school, we didn't have owls, although i do have a pegasus and one large dog." He had a pegasus! But they are nearly imposable to train! I guess he was right when he said he was good with animals.<p>

"So, lead the way sir Ronald." Percy said dramatically, pointing of into the distance.

"Seriously Perce, if you don't stop calling me that, i might just skin you." Percy looked at me in feigned shock.

"Whatever do you mean Ronald?" He asked a smirk creeping up on his face.

"Right thats it!" All of a sudden we were engaged in a high speed chase, and damn Percy was fast. Surprisingly he managed to stop right out outside the pet store. When I caught up, Percy was stood at the door, looking as if we hadn't just run for 6 minutes, whilst I was on the floor, huffing and puffing. Yep, he defiantly needs to be on the Quiditch team.

PERCY POV/p

We walked into the door, and I immediately heard hundreds of tiny voices. I dropped to floor clutching ears, trying to block the noise out.

**Oh look a demi-god**

**You think he'll buy one of us?**

**Shush I think he understands us.**

I wasn't sure who was speaking, but I knew they weren't human. All of a sudden one voice sounded out over all of them.

_Perseus._

Lady Hecate? I asked in my mind. Not sure how, but she must have heard it.

_Percy, that wand i gave you, because it has a monster scale in it, it has given you the power of parsle-tongue._

Parsle-tongue?

_Snake speak. If you want to master it, I suggest getting a snake, i'm sure my son will make an exception._

Okay, thanks Hecate. There was a small pull, and I knew Hecate had gone. Now I knew that the voices were snakes, it was easier to handle them. I slowly stood up only to find Ron looking at me worryingly.

"Blimey what was that all about?" He asked as we made our way towards the snakes.

"Oh that. Sometimes the snakes can get a bit over whelming." I shrugged him off. He stopped momentarily when he saw where we were, then sped up to come in line with me.

"What do you mean?" With all these snake voices in my head, and Ron talking out loud it was getting really hard to concentrate.

"Oh did i not tell you? I'm a parsle-tongue." His jaw practically hit the floor. Instead of facing the flood of questions, I decided to set out on finding my new friend. My eyes scanned all the cages, but no snake stood out to me. That was until I came across one particular snake. I read the label:

_Female,_

_Green python,_

_Highly venomous,_

_5'3 long,_

_1 year old,_

_This female has never had a human owner. Be warned, this snake is not for beginers. She has a special affinity to water and healing magic._

_Despite the warning, i couldn't help but talk to her._

:hello: I hissed. Wow, never knew I could do that. She popped her small green head up, her sea-green eyes peering at me inquisitively.

**Hello, young sir. May I help you**. She asked. Who knew snakes could be so polite.

:please call me Percy, and I was hoping to purchase you. Would you mind?: she tilted her head slightly to the side in confusion.

**Did you not read my label? Are you not afraid of me son of Poseidon?** She asked. In all honesty I was amazed that she knew my parentage, but I suppose its an animal thing.

:yes, but no, you don't scare me. In fact, you kind of amaze me. Especially with your affinity to water magic: She looked away wistfully for a moment, then returned her gaze to me.

**Okay then Percy, it would, in fact, be a great honour to be your snake. Especially considering your wands rarity and power.** This snake was really smart. Looks like we have another Hermionie. I picked her cage up, earning many frightened stares, and made my way towards the counter.

:what's your name?: I asked her. She looked up at me and shook her head sadly.

**I don't have one**. She hissed

:how about Kymata. It means waves in Greek: she looked up at me with wide eyes and nodded vigerously.

**I like that**. With that I placed Ky down on the counter. The shop tenant looked at me sceptically.

"Are you sure you want this one? She can be quite a handful." He said, I shook my head and smiled.

"Na, Ky just needed someone to talk to." His eyes widened for a second, before he nodded his head in understanding. I quickly payed for Ky with the money Chiron gave me and left, Ron hurrying after me. He looked fearfully at Ky.

"Did you have to get the most dangerous snake in there?" Ky and I laughed at him, causing him to jump out of his skin.

"No. Ky is actually very nice. I doubt she would ever hurt anyone." Ron looked at me then Ky, then me and finally said.

"So Ky?" I nodded.

"Her full name is Kymata, meaning Waves in greek." Ron nodded his head, knowing my love of the sea. We quickly collected our books, robes and me an owl, which I forgot to get earlier, which I named Revma, meaning current, or just Rev for short. When we joined back up with the others, everyone but Harry eyed Ky skeptically.

:Hello: Harry hissed. Never knew he was a parsle-tongue.

**Hi**. Ky hissed at him. Molly looked between me, Harry and Ky.

"Umm, Percy. Why did you buy a snake?" Arthur asked. I looked down a Ky and smiled slightly.

"Because I'm a parsle-tongue. My old professor wanted me to buy a snake to learn parsle-magic." Everyones jaw drooped and Harry smiled at me. Obviously my guess at parsle-magic was right.

"What's her name?" He asked. I smiled at him, liking that we finally found common ground. After all i was supposed to be protecting him.

"Kymata, it means Waves in greek. She's a green python." At that everyone took a minimal step backwards, causing me Harry and Ky to laugh.

"No need to worry. She is probably the most docile snake I have ever seen." Harry said. His words were obviously enough for Hermione. She ran forward and peered at Ky.

"Isn't green pythons venom fatal?" She asked. Ky nodded, causing Hermione to jump. I laughed at that.

"Yeah, but she said she won't bite anyone. Should we be leaving?" I asked as I noticed the sun starting to set. Molly looked up and jumped.

"Oh yes. We are incredibly late. To the floo network now!" Molly said, all her previous fear of Ky turned to angst. We all rushed towards the floo network, and disappeared in a bright green light.


End file.
